Children have become weaker and unable to do physical tasks that previous
generations found easy, a study has found.

Experts said today's 10-year-olds had less muscular strength than children born a decade before, because instead of spending time climbing trees and climbing ropes, their leisure is spent indoors playing on computers.

The findings, published in the child health journal Acta Paediatrica, found children could do fewer sit-ups and were less able to hang from wall bars in a gym.

As well as the decline in arm strength, the study found they were less able to grip an object firmly.

The study led by Dr Gavin Sandercock, a children's fitness expert at Essex University, studied how strong a group of 315 Essex 10-year-olds in 2008 were compared with 309 children the same age in 1998.

It found the number of sit-ups 10-year-olds can do declined by 27.1 per cent, arm strength fell by 26 per cent, grip strength by 7 per cent.

While one in 20 children could not hold their own weight while hanging from the wall bars in 1998, a decade later, one in 10 could not manage it.

Dr Sandercock said: "This is probably due to changes in activity patterns among English 10-year-olds, such as taking part in fewer activities like rope-climbing in PE and tree-climbing for fun."

"Typically, these activities boosted children's strength, making them able to lift and hold their own body weight."

The fact that 10 per cent could not do the wall bars test and another 10 per cent refused to try was "really shocking", he said.

"That probably shows that climbing and holding their own weight was something they hadn't done before."

The study found the two groups of children had the same body mass – meaning that the current group of 10-year-olds must have had more fat and less muscle than their predecessors.

Dr Sandercock said the findings were "really worrying".

Tam Fry, of the Child Growth Foundation, said: "Climbing trees and ropes used to be standard practice for children, but school authorities and 'health and safety' have contrived to knock the sap out of our children."

"Falling off a branch used to be a good lesson in picking yourself up and learning to climb better. Now fear of litigation stops the child climbing in the first place."

A Department of Health spokeswoman said the government had introduced several programmes promoting active lifestyles among the young, and the health survey for England reported back on physical activity levels. She added: "The Department of Health has no current plans to introduce fitness testing for children."